In this study, vapor condensation heat transfer rate of iso-butane over plain tube and 24 fins per inch (fpi) finned tube placed horizontally was determined experimentally and results were compared to get optimum heat transfer coefficient (HTC). Condensation heat transfer coefficients of R-600a showed the trend that external condensation HTCs decrease as wall sub cooling temperatures increase. All data were taken under saturation temperatures of 39 °C with wall sub-cooling of 5-12 °C on a tube of 19 mm outside diameter under a heat flux of 11-55 kW/m². Based upon the Data taken in this study, different graphs are plotted varying different parameters to show their dependency on other parameters.